Secrecy is alluring! Already early anthropologists showed great interest in secret knowledge and secret societies, and, in the age of Wikileaks and the ongoing Internet privacy debate, the issue is still high on the list. The companion volume to the exhibition of the same title at the Museum der Kulturen Basel (13 April 2018 to 21 April 2019) looks at secrecy from the perspective of social order. Secrecy creates boundaries between insiders and outsiders, between the informed and the uninformed. Access to secret knowledge means power, revealing it spells danger.Contributions from current research in diverse fields uncover how secrecy comes into effect in different cultural settings, while in-depth portraits of arcane objects from the collections of the Museum der Kulturen Basel reveal that secrets not only have a hidden but very often also a visible, public dimension.